1. Field of the Invention
This invention relates to an image sensing apparatus and, more particularly, to an image sensing apparatus which can obtain still images of high resolution in the vertical direction.
2. Description of the Prior Art
Many types of image sensing apparatus have been developed and commercialized for television signals. Yet, since they are designed in adaptation to the television system such as NTSC or PAL or SECAM, the resolution in the vertical direction is not high enough. In other words, the NTSC system has a field of about 480 lines in the vertical direction, and the PAL or SECAM system is of about 560 lines.
On the other hand, as the video-related technology is spreading, such a new technology that a video signal is used for printing a still picture on a sheet of paper has been proposed, where a problem arises that for a case of requiring a resolution of, for example, 16 lines/mm, the use of the conventional image sensing apparatus of the NTSC type can only realize a size of picture on the order of 3 cm in vertical length. Also, if the size is unduly enlarged, the roughness of texture of the printed picture undersirably increases.
Also, as the unified form of an image sensing apparatus with a video recorder for recording the output signals of that apparatus, there are publicly known the electronic still camera and the 1/2 in. VTR type movie camera. The image sensing apparatus used in these cameras, or the video camera, too, is of the type that video signals for the television system are produced.
Thus, the conventional image sensing apparatus, because of making its output or video signals conform to the television standards, is insufficient in the point of the resolution in the vertical direction and cannot be used particularly when the image quality of the obtained picture is desired to be high.